Radiator and related methods



2 Sheets-Sheet 1 INVENTORS 1966 N, E. LINDSTRAND ETAL RADIATOR AND RELATED METHQDS Filed Nov. 26, 1965 k ,gi,

FIG. 1

N/LS ER/k L/IVDSTRA/VD ROLF GUNNAR SU/VDBERG 55km; Nd- 3a? I37: W

1966 N. E. LINDSTRAND ETAL 3,232,343

RADIATOR AND RELATED METHODS 2 Sheets$heet 2 Filed Nov. 26, 1963 FIG. 4

INVENIORS N/LS ERIK LINDSTRA/VD ROLF GUN/VAR SU/VOBERG' Semis N"- 3.26, 02%

United States Patent ()fiice 3,232,343 Patented Feb. .1, 1966 This invention relates to improved radiators and to mproved methods for manufacturing radiators with lfllPIOVSdCllfll'flClEIlSllCS, as Well as to methods for providing improved alloys for use in radiator structures and the like.

It is an object of the invention to provide an improved radiator construction, especially suitable for use in the automobile industry, such structure being of relatively reduced weight without suffering any loss of cooling efficiency.

It is a further object of the invention to provide an improved radiator construction fabricated of a material having a thermal conductivity comparable to known structures, while having an improved tensile strength and ductility.

It is a further object of the invention to provide an improved method of manufacturing radiator structures by providing sufficient tensile'strength and ductility to permit making, for example, air fins with bosses and slits to increase turbulence without affecting-the other desirable characteristics .of the radiator structure.

It is still another object of the invention to provide improved techniques to enable the reduction of the gauge of air fins and the like without causing a loss of strength.

Yet another object of the invention is to provide improved. techniques whichavoid the cracking of the radiator structure material during manufacturing processes.

Still another 'objectof the invention is'to provide improved techniques in accordance with'which there will be no grain size change or change of directional properties during manufacturing processes.

In the manufacturing of radiator structures according to preferred techniques attempts are made to increase coolingcaipacity per-unit weight by making elements of the radiator structure with .detents or bumps and/or slits which tend to weaken the structure and tend to complicate the manufacturing processes by changing tensile strength and ductility characteristics as well as the heat conductivity of the materials employed.

It is known to add elements to the pure copper which generally constitutes the material employed in an effort to provide sufiicient tensile'strength to enable the material to be processed as aforesaid.

Such components usually result in a reduced thermal conductivity and as well in a reduced ductility. The

material employed, therefore, readily cracks as it is being shaped.

It has'now been found, according to the invention, that smallquantities of cadmium added to deoxidized copper will give an unexpected high tensile strength to the illustrated in the accompanying of azradiator structure according structure "employing the alloy of comb structure employing the alloy 1constructiomespecially suitable for u weight. However, an improved result is obtained according to the invention by using cadmium and phosphorous incombination as deoxidizers.

it has also proved that a similar result can be obtained -by using cadmium and lithium in combination as deoxidizers.

Sometypical alloys are the following:

(1) Copper and .2% by weight of cadmium (2.) Copper and .2% by weight of cadmium and an addition of 005 to 010% by weight'of phosphorous.

(3) Copper and .2% by weight of cadmium and an addition of .010 to 020% by weight of lithium.

According to the invention, an alloy is formed ofdeoxidized copper and .05 to 2% by weight of cadmium,

the amount of cadmium preferably employedbeing-within .therrange of..1 to 3% byweight.

According to the invention, an alloy is formed of copper which is deoxidized by adding .005 to 015% by weight of phosphorous and .05 to 2% by weight of cadmium, the amount of cadmium preferably employed being Withinthe range of .1 to 3% by weight.

According to the invention, an alloy is formed of copper which is deoxidized by adding .01 to 02% .by weight of lithium and .05 to 2% by weight ofcadmium, the amount of cadmium preferably employed being within the range of .1 to .3% by weight.

According to the invention, 'the alloy may be .rolled into thin strips or foil having a thickness of about .01 mm. to .15 mm.

The strips or foil thus formed may be bent to any suitable form for constituting a component of a radiator structure and are found to have sufiicient tensile strength and ductility to permit any conventional operation to be performedthereon. Moreover, the total weight of the 'has'been found that a reductionin weight of about 20% causes a loss of coolingcapacity of less than about 5 Somepreferred embodiments ofthe invention in which the aforesaid alloy may preferably be employed are drawing in which: FIGURE 1 illustrates in perspective view a component tothe invention; FIGURE 2 illustrates in perspective view a honeycomb the invention; and

FIGURE 3 illustrates a second honeycomb structure embodying the alloy of the invention.

PTGURE 4 illustrates a third embodiment of a'honeyof the invention.

FIGURE 5 illustrates in a perspective view of radiator se in the automobile industry, with a honeycomb structure employing the alloy of the invention.

The radiator structure component illustrated in FIG- URE 1 comprises generally a sheet ltlhaving a generally zig-zag form and in the face of which are provided a multitude of embossments or dents 11. Said sheeting or foil 10 has a multitude of fold lines 12 and is intended to be incorporated into a honeycomb structure as will be shown in greater detail hereinafter.

The bumps of FIGURE 1 are intended to create a turbulence which enhances the cooling efficiency of the structure. It Will be appreciated, however, that these embossrnents, as Well as the multitude of fold lines, require a material with superior tensile strength and ductility to avoid problems during mass production of such components.

The honeycomb radiator structure of FIGURE 2 comprises a plurality of sheets 13, having a multitude of bumps or dents 14 therein, the sheets 13 being spaced in horizontal disposition and having passed therethrough a plurality of vertical water tubes 15 welded or soldered thereto, the tubes 15 having a flattened cross-section in this embodiment of the invention.

In assembling such a structure it may be found that when conventional techniques are employed the soldering or welding tends to cause a grain structure change or growth which is to be avoided if the strength of the overall structure is to be retained. It is an object of the invention to avoid this grain size change so that optimum structural strength can be realized.

In the embodiment of FIGURE 3, a honeycomb structure comprising a plurality of elements 16 is illustrated, there being included in the structure a plurality of vertically disposed water pipes 17 welded thereto. The zigzag structures are provided with a multitude of slots 18, the purpose of which is to increase the radiating surface area of the structure and to create a turbulence to increase the cooling efliciency of the device.

In the embodiment of FIGURE 4, a honeycomb structure comprising a plurality of elements 19 is illustrated, there being included in the structure between adjacent elements vertical pairs of corrugated partitions 20, 21 lying close to each other to form flow passages 22 between them. Said pairs of partitions are mutually the image of each other and in addition to. the wave-like corrugations they are also provided with elongated embossments 23 and 24. Pairs of such embossments 23 and 24 are arranged in vertical rows which communicate with each other via intervening grooves 25 so as to form the passageways referred to above.

FIGURE illustrates a radiator for the automobile industry incorporating as indicated by reference numeral 26 a honeycomb structure employing the alloy of the invention. In this figure reference numeral 27 designates the upper header and 28 the lower header mutually connected through the pipes 15 and 17 respectively or the passages 22 and further connected, respectively, to the engine block via pipe connections 29 and 30 in a conventional way.

To enable the unusual configurations necessary to radiator structures of the aforesaid type, the invention contemplates the use of a special alloy. This special alloy involves the combining with deoxidized copper of .05 to 2% by weight of cadium, the amount of cadmium employed preferably lying within the range of .1 to .3% by weight.

As has been indicated above, the alloy of the invention may b rolled into thin strips or foil with a thickness of about .10 mm. to .15 mm., this material having sufficient tensile strength and ductility to enable any of the aforesaid configurations to be manufactured with ease without changing the directional characteristics thereof and without resulting in a change of grain size during manufacture.

The reduced gauge permissible with the alloy of the invention permits a significant reduction in weight of the radiator structure without a corresponding decrease in thermal capacity. The invention, moreover, avoids the defects of the additives previously employed in that it helps rather than harms the thermal conductivity and ductility of the resulting alloy and avoids cracking when the alloy is formed into the peculiar shapes required for radiator structures.

It will be appreciated that upon formation of the above alloy it is then rolled into thin strips or foil and is then formed with embossments, dents or slits or by being bent by means of rotating or stamping tools, during which process the material can be bent to suitable sizes to which will be soldered or :welded suitable tubes or flow passages serving for accommodating a cooling fluid.

The alloy of the invention provides that the material will have the same strength and elongation in all direactions in order to avoid hairline cracks and the like when the material is formed.

An additional very important advantage of the invention is that it has a higher softening temperature. This permits the use of increased soldering temperatures without any loss in strength and therefore substantially reduces the soldering time for radiator structures. This contributes materiallyto minimizing costs and contributes substantially to mass production technique.

In summary the invention according to one aspect thereof, relates to a method of improving the properties of copper for use in a radiator, which method comprises alloying deoxidized copper with .05 to 2% by weight of cadmium, the copper constituting from about 98 to 99.95% of the remainder. Preferably the amount of cadimium is restricted to .1 to 3% by weight and the resulting alloy is preferably rolled into a strip of about .10 mm. to .15 mm.

According to another aspect of the invention, it relates to a method of improving a radiator design adapted for employing copper sheeting of minimum determinable thickness, the method of the invention comprising alloying cadmium with deoxidized copper and using a sheeting of the resulting alloy at less than said determinable thickness.

According to still another aspect of the invention, there is contemplated a method of improving the tensile strength and ductility of copper while maintaining the heat conductivity properties thereof by alloying deoxidized copper with .05 to 2% by weight of cadmium, rolling the resulting alloy into a strip and forming a radiator part out of said strip such as by forming embossments, dents or slits therein, as has been described above.

In accordance with still another aspect of the invention, there is contemplated a method of minimizing the weight of a radiator while maintaining the strength thereof by forming the radiator from a sheeting of the aforedescribed alloy.

Other aspects of the invention relate to honeycomb structures formed of the above-noted alloy and/ or the use of and provision of articles of manufacture comprising a sheet of an alloy of deoxidized copper and cadmium preferably in combination with phosphorus or lithium in the above-described proportions.

There will now be obvious to those skilled in the art many modifications and variations of the structures and methods set forth above. These modifications and variations will not depart from th scope of the invention if defined by the following claims.

What is claimed is:

1. A radiator structure comprising means for conveying a fluid medium, and a honeycomb structure in said means in heat exchange relation therewith, said honeycomb stmcture including an assembly of relatively thin spaced copper elements of a thickness of .01 to .15 mm. defining parallel air passages, each element being of an alloy consisting of deoxidized copper with 0.05 to 2% by weight of cadmium and 0.005 to 0.015% by weight of phosporus.

2. A radiator structure comprising means for conveying a fluid medium, and a honeycomb structure in said means in heat exchange relation therewith, said honeycomb structure including an assembly of relatively thin spaced copper elements of a thickness of .01 to .15 mm. defining parallel air passages, each element being of an alloy consisting of deoxidized copper with 0.05 to 2% by weight of cadmium and 0.01 to 0.02% by weight of lithium.

References Cited by the Examiner UNITED STATES PATENTS 820,954 5/1906 Chaudoir 153 1,307,642 6/1919 Smith 75--l53 1,434,853 11/1922 Spery --148 Other references on following ave UNITED STATES PATENTS Jones et a1 75-153 Pol-and 75-153 XR Hensel et a1. 75-153 Hensel et a1. 75153 Seemiller 165152 Pruna 75-153 6 FOREIGN PATENTS 568,275 3/1945 Great Britain.

ROBERT A. OLEARY, Primaiy Examiner.

CHARLES SUKALO, Examiner.

M. A. ANTONAKAS, Assistant Examiner. 

1. A RADIATOR STRUCTURE COMPRISING MEANS FOR CONVEYING A FLUID MEDIUM, AND A HONEYCOMB STRUCTURE IN SAID MEANS IN HEAT EXCHANGE RELATION THEREWITH, SAID HONEYCOMB STRUCTURE INCLUDING AN ASSEMBLY OF RELATIVELY THIN SPACED COPPER ELEMENTS OF A THICKNESS OF .01 TO .15 MM. DEFINING PARALLEL AIR PASSAGES, EACH ELEMENT BEING OF AN ALLOWY CONSISTING OF DEOXIDIZED COPPER WITH 0.05 TO 2% BY WEIGHT OF CADMIUM AND 0.005 TO 0.015% BY WEIGHT OF PHOSPORUS. 